Hello.
I have a 1 and a half story house on a full basement which is doubles as a garage. The first 3rd of the basement/ garage ceiling is insulated. -The front part over the garage door. The furnace is in the basement which keeps it around 40-50ish down there, depending how cold it is outside. I live in Binghamton NY. The overhead door is insulated but is colder by it. I park in the garage daily. Most of the basement is underground with the exception of the front wall with the overhead door.
My question is would it worth insulating the other 2/3's of the basement ceiling to save on heating? I found 23" by 8" think insulation that would work. The floor joices are 21" apart inside length and 8" deep. The ducts (forced hot air) are not insulated which helps keep the garage warmer. I do use the basement occasionally for working on my toys and using my bar down there/playing beer pong/partying. Any help would be much appreciated.

gregzoll

01-18-2011 08:50 PM

First question is, is there a wall separating the garage space from the basement? If there is not, then you really can not use the garage to park vehicles or lawn equipment in it. If it does have a wall, then the first thing I would do, is assess how much it costs for Spray foam vs. Roxwool, and how much for 5/8" drywall to be put up & joints taped & mudded. You can follow the info at buildingscience.com per insulating basement/crawl spaces, which would also apply to attached garage space, but keep in mind that the XPS foam board has to be covered with Gypsum to consider it firesafe.

WS6transAm

01-18-2011 09:52 PM

There's no wall barrier. It's a tandem garage so I can fit 2 cars deep in it and I have 3 motorcycles in it now so I'm not really planning on putting up a wall because I wouldn't be able to fit everything in it. I'm just concerned with the insulation on the ceiling right now. Thanks for your input.

gregzoll

01-19-2011 07:46 AM

If there is no dividing wall from the living area (ie basement), I would get that up first with a Fireproof door. Then you can go about with either putting Roxwool on the walls, and Sprayfoam on the Ceiling. As stated before, because there is no separating barrier from living to garage space, it can not be considered a garage.